Kato Ikuko, Lane Dorothy, Womack Catherine R, Bock Cathryn H, Hou Lifang, Lin Jennifer H, Wu Chunyuan, Beebe Dimmer Jennifer, Simon Michael S
a Department of Oncology , Karmanos Cancer Institute at Wayne State University School of Medicine , Detroit , Michigan , USA.
b Department of Pathology , Wayne State University School of Medicine , Detroit , Michigan , USA.
J Am Coll Nutr. 2017 Aug;36(6):462-469. doi: 10.1080/07315724.2017.1321505. Epub 2017 Jul 6.
The Women's Health Initiative (WHI) Dietary Modification (DM) trial did not show that reductions in dietary fat accompanied by increases in vegetable and fruit consumption decrease the incidence of colorectal cancer. Secondary analyses suggested that aspirin use may modify the intervention effects of DM on colorectal cancer development, although a recent reanalysis including the postintervention period confirmed no main effect of the intervention on reducing colorectal cancer incidence Methods: We analyzed data from 48,834 postmenopausal women who were randomized into the low-fat DM (N = 19,540) or comparison (N = 29,294) group for an average 8.1 years and followed for an additional 9.4 years through August 31, 2014. Exposure to specific class(es) or strength(s) of nonsteroidal anti-inflammatory drugs (NSAIDs) was modeled at baseline and as time-dependent use through the 9-year clinic visit. A Cox proportional hazard model was employed to assess the association of the DM, medication use, and their interaction with colorectal cancer events.
A total of 906 incident cases of colorectal cancer were identified during the intervention and postintervention periods. By both exposure models, we found that colorectal cancer incidence was not different in the DM from the comparison group among any type of NSAID users. None of the interactions with any category of NSAID use was statistically significant; however there was most modest evidence for an interaction (p = 0.07) with aspirin use at baseline (hazard ratio [HR] = 0.81, 95% confidence interval [CI], 0.60-1.11 for users; HR = 1.12, 95% CI, 0.97-1.30 for nonusers). Strength and duration of aspirin use at baseline did not alter the associations.
Extended follow-up of women in the WHI DM trial did not confirm combined protective effects of aspirin and low-fat diet on colorectal cancer risk among the postmenopausal women.
妇女健康倡议（WHI）饮食调整（DM）试验并未表明，伴随蔬菜和水果摄入量增加的膳食脂肪减少可降低结直肠癌的发病率。二次分析表明，使用阿司匹林可能会改变DM对结直肠癌发生的干预效果，尽管最近一项包括干预后期的重新分析证实，该干预对降低结直肠癌发病率没有主要影响。方法：我们分析了48834名绝经后妇女的数据，她们被随机分为低脂DM组（N = 19540）或对照组（N = 29294），平均随访8.1年，并在2014年8月31日前额外随访9.4年。在基线时以及通过9年的门诊就诊作为时间依赖性使用情况，对非甾体抗炎药（NSAIDs）的特定类别或强度的暴露情况进行建模。采用Cox比例风险模型评估DM、药物使用及其相互作用与结直肠癌事件之间的关联。
在干预期和干预后期共确定了906例结直肠癌病例。通过两种暴露模型，我们发现，在任何类型的NSAIDs使用者中，DM组的结直肠癌发病率与对照组没有差异。与任何NSAIDs使用类别之间的相互作用均无统计学意义；然而，有最微弱的证据表明与基线时使用阿司匹林存在相互作用（p = 0.07）（使用者的风险比[HR] = 0.81，95%置信区间[CI]，0.60 - 1.11；非使用者的HR = 1.12，95%CI，0.97 - 1.30）。基线时阿司匹林使用的强度和持续时间并未改变这些关联。
对WHI DM试验中女性的长期随访未证实阿司匹林和低脂饮食对绝经后女性结直肠癌风险具有联合保护作用。
